So I've been taking ballroom dancing lessons with my boyfriend and we were trying to do an overhead lift (similar to Dirty Dancing). He can get me up without a problem and we can hold it with no hands on his shoulders for a very brief period but then I start falling forward and he has to lower me down.

Does anyone have any idea why this might be happening? I'm assuming it's a form/technique issue since he's strong enough to easily hold me up much longer.

Perhaps you need to figure out where your "center" of weight distribution is in your body. Do you have more length in your legs or in your torso? Depending on that answer, maybe he needs to lift you lower/higher on your hip or rib cage. For instance, if you have a long torso and he's lifting you from a point low on your hip, maybe that's why you're falling forward; so then you'd want to have him try lifting you from a point nearer to your rib cage.

it might be also the hand postition of his hands on your body ie spreading his hands on the poitit point .also you can get him to hold you in position but tilt you forward and then return to the flat position and you can turn the lady to right and left as this can count-weight the margin correction of hand hold .